$i.$ Six codons do not code for any amino acid.
$ii.$ Codon is read in $mRNA$ in a contiguous fashion.
$iii.$ Three codons function as stop codons.
$iv.$ The initiation codon $AUG$ codes for methionine.
$(i)$ $RNA$ can directly code for the synthesis of proteins
$(ii)$ It is very common process to synthesis $DNA$ from $RNA$
$(iii)$ $RNA$ is used as genetic material only in human
$(iv)$ One polynucleotide chain is present in $RNA$